fix: Cardinality overflow to use bool value instead of string (#2916)

Author: cijothomas

opentelemetry-sdk/CHANGELOG.md

@@ -18,8 +18,11 @@ also modified to suppress telemetry before invoking exporters.
   - This feature was previously removed in version 0.28 due to the lack of
     configurability but has now been reintroduced with the ability to configure
     the limit.  
-  - There is ability to configure cardinality limits via Instrument 
+  - There is ability to configure cardinality limits via Instrument
     advisory. [#2903](https://github.com/open-telemetry/opentelemetry-rust/pull/2903)
+  - Fixed the overflow attribute to correctly use the boolean value `true`
+    instead of the string `"true"`.
+    [#2878](https://github.com/open-telemetry/opentelemetry-rust/issues/2878)
 
 - *Breaking* change for custom `MetricReader` authors.
   The `shutdown_with_timeout` method is added to `MetricReader` trait.

opentelemetry-sdk/src/metrics/internal/mod.rs

@@ -23,7 +23,7 @@ pub(crate) static STREAM_OVERFLOW_ATTRIBUTES: OnceLock<Vec<KeyValue>> = OnceLock
 
 #[inline]
 fn stream_overflow_attributes() -> &'static Vec<KeyValue> {
-    STREAM_OVERFLOW_ATTRIBUTES.get_or_init(|| vec![KeyValue::new("otel.metric.overflow", "true")])
+    STREAM_OVERFLOW_ATTRIBUTES.get_or_init(|| vec![KeyValue::new("otel.metric.overflow", true)])
 }
 
 pub(crate) trait Aggregator {

opentelemetry-sdk/src/metrics/mod.rs

@@ -123,6 +123,7 @@ mod tests {
     use data::GaugeDataPoint;
     use opentelemetry::metrics::{Counter, Meter, UpDownCounter};
     use opentelemetry::InstrumentationScope;
+    use opentelemetry::Value;
     use opentelemetry::{metrics::MeterProvider as _, KeyValue};
     use rand::{rngs, Rng, SeedableRng};
     use std::cmp::{max, min};
@@ -2400,8 +2401,7 @@ mod tests {
         assert_eq!(sum.data_points.len(), 2002);
 
         let data_point =
-            find_sum_datapoint_with_key_value(&sum.data_points, "otel.metric.overflow", "true")
-                .expect("overflow point expected");
+            find_overflow_sum_datapoint(&sum.data_points).expect("overflow point expected");
         assert_eq!(data_point.value, 300);
 
         // let empty_attrs_data_point = &sum.data_points[0];
@@ -2449,8 +2449,7 @@ mod tests {
             // For cumulative, overflow should still be there, and new points should not be added.
             assert_eq!(sum.data_points.len(), 2002);
             let data_point =
-                find_sum_datapoint_with_key_value(&sum.data_points, "otel.metric.overflow", "true")
-                    .expect("overflow point expected");
+                find_overflow_sum_datapoint(&sum.data_points).expect("overflow point expected");
             assert_eq!(data_point.value, 600);
 
             let data_point = find_sum_datapoint_with_key_value(&sum.data_points, "A", "foo");
@@ -2506,8 +2505,7 @@ mod tests {
         assert_eq!(sum.data_points.len(), cardinality_limit + 1 + 1);
 
         let data_point =
-            find_sum_datapoint_with_key_value(&sum.data_points, "otel.metric.overflow", "true")
-                .expect("overflow point expected");
+            find_overflow_sum_datapoint(&sum.data_points).expect("overflow point expected");
         assert_eq!(data_point.value, 300);
 
         // let empty_attrs_data_point = &sum.data_points[0];
@@ -2555,8 +2553,7 @@ mod tests {
             // For cumulative, overflow should still be there, and new points should not be added.
             assert_eq!(sum.data_points.len(), cardinality_limit + 1 + 1);
             let data_point =
-                find_sum_datapoint_with_key_value(&sum.data_points, "otel.metric.overflow", "true")
-                    .expect("overflow point expected");
+                find_overflow_sum_datapoint(&sum.data_points).expect("overflow point expected");
             assert_eq!(data_point.value, 600);
 
             let data_point = find_sum_datapoint_with_key_value(&sum.data_points, "A", "foo");
@@ -2605,8 +2602,7 @@ mod tests {
         assert_eq!(sum.data_points.len(), cardinality_limit + 1 + 1);
 
         let data_point =
-            find_sum_datapoint_with_key_value(&sum.data_points, "otel.metric.overflow", "true")
-                .expect("overflow point expected");
+            find_overflow_sum_datapoint(&sum.data_points).expect("overflow point expected");
         assert_eq!(data_point.value, 300);
 
         // let empty_attrs_data_point = &sum.data_points[0];
@@ -2654,8 +2650,7 @@ mod tests {
             // For cumulative, overflow should still be there, and new points should not be added.
             assert_eq!(sum.data_points.len(), cardinality_limit + 1 + 1);
             let data_point =
-                find_sum_datapoint_with_key_value(&sum.data_points, "otel.metric.overflow", "true")
-                    .expect("overflow point expected");
+                find_overflow_sum_datapoint(&sum.data_points).expect("overflow point expected");
             assert_eq!(data_point.value, 600);
 
             let data_point = find_sum_datapoint_with_key_value(&sum.data_points, "A", "foo");
@@ -2838,6 +2833,14 @@ mod tests {
         })
     }
 
+    fn find_overflow_sum_datapoint<T>(data_points: &[SumDataPoint<T>]) -> Option<&SumDataPoint<T>> {
+        data_points.iter().find(|&datapoint| {
+            datapoint.attributes.iter().any(|kv| {
+                kv.key.as_str() == "otel.metric.overflow" && kv.value == Value::Bool(true)
+            })
+        })
+    }
+
     fn find_gauge_datapoint_with_key_value<'a, T>(
         data_points: &'a [GaugeDataPoint<T>],
         key: &str,